Back in the day, many European countries had registers of known communist and socialist sympathizers. They where used to keep communists out of government and union jobs. Those in the registers had a harder time getting promoted, was fired for spurious reasons and so on. The other effect it had is that people became frightened to voice their support of communists lest they also be placed in the register and having their careers ruined.<p>It is not far-fetched to think that broad intelligence gathering will be used in the exact same way today. Communism may not be the big boogieman it once way, but there are still ideologies and causes that can get you branded as undesirable. For example, by being drug liberal.<p>I think it's naive to think that the information they are collecting will go unused. There aren't enough terrorist threats in there to act upon, so they will focus on the secondary threats which is people with the wrong opinions.